<form method="get" id="searchform" action="<?php echo esc_url( home_url( '/' ) ); ?>">
    <input type="text" class="search-field" name="s" id="s" placeholder="<?php esc_attr_e( '搜索你感兴趣的'); ?>" />
    <input type="submit" class="search-submit" />
</form>